Sunitinib in patients with metastatic renal cell carcinoma

Anti-angiogenesis therapies: their potential in cancer management

Angiogenesis plays an important role in normal animal growth and development. This process is also vital for the growth of tumors. Angiogenesis inhibitors have a different mechanism of action to traditional chemotherapy agents and radiation therapy. The angiogenesis inhibitors can act synergistically with conventional treatments and tend to have non-overlapping toxicities. There are four drugs which have a proven role in treating cancer patients. Bevacizumab is a humanized monoclonal antibody that binds to and neutralizes vascular endothelial growth factor (VEGF). Sunitinib and sorafenib inhibit multiple tyrosine kinase receptors that are important for angiogenesis. Thalidomide inhibits the activity of basic fibroblast growth factor-2 (bFGF). The licensed indications and the supporting evidence are discussed. Other drugs are currently being tested in clinical trials and the most promising of these drugs are discussed. Aflibercept, also known as VEGF-trap, is a recombinant fusion protein that binds to circulating VEGF. The vascular disrupting agents act by targeting established blood vessels. These exciting new treatments have the potential to transform the management of cancer.

Sunitinib for the management of advanced renal cell carcinoma

Targeted agents, such as sunitinib (SUTENT((R))) have become central to the management of advanced and/or metastatic renal cell carcinoma (mRCC). Sunitinib is an oral, multitargeted receptor tyrosine kinase inhibitor that has demonstrated efficacy for the treatment of mRCC in multiple clinical trials. In a Phase III trial in previously untreated patients with mRCC, sunitinib was associated with median progression-free survival of 11 months, which was more than double that observed with interferon-alpha (5 months; p < 0.001). As a result, sunitinib is recommended in international treatment guidelines and is considered a reference standard of care in the first-line setting for patients at favorable or intermediate prognostic risk. Sunitinib is generally well tolerated with a predictable adverse-event profile; the majority of adverse events can be managed with standard medical intervention. This paper presents an overview of data supporting the use of sunitinib for mRCC, and considers the optimal management of sunitinib in clinical practice.

Novel SHP-1 inhibitors tyrosine phosphatase inhibitor-1 and analogs with preclinical anti-tumor activities as tolerated oral agents

Src homology region 2 domain-containing phosphatase 1 (SHP-1) has been implicated as a potential cancer therapeutic target by its negative regulation of immune cell activation and the activity of the SHP-1 inhibitor sodium stibogluconate that induced IFN-gamma(+) cells for anti-tumor action. To develop more potent SHP-1-targeted anti-cancer agents, inhibitory leads were identified from a library of 34,000 drug-like compounds. Among the leads and active at low nM for recombinant SHP-1, tyrosine phosphatase inhibitor-1 (TPI-1) selectively increased SHP-1 phospho-substrates (pLck-pY394, pZap70, and pSlp76) in Jurkat T cells but had little effects on pERK1/2 or pLck-pY505 regulated by phosphatases SHP-2 or CD45, respectively. TPI-1 induced mouse splenic-IFN-gamma(+) cells in vitro, approximately 58-fold more effective than sodium stibogluconate, and increased mouse splenic-pLck-pY394 and -IFN-gamma(+) cells in vivo. TPI-1 also induced IFN-gamma(+) cells in human peripheral blood in vitro. Significantly, TPI-1 inhibited ( approximately 83%, p < 0.002) the growth of B16 melanoma tumors in mice at a tolerated oral dose in a T cell-dependent manner but had little effects on B16 cell growth in culture. TPI-1 also inhibited B16 tumor growth and prolonged tumor mice survival as a tolerated s.c. agent. TPI-1 analogs were identified with improved activities in IFN-gamma(+) cell induction and in anti-tumor actions. In particular, analog TPI-1a4 as a tolerated oral agent completely inhibited the growth of K1735 melanoma tumors and was more effective than the parental lead against MC-26 colon cancer tumors in mice. These results designate TPI-1 and the analogs as novel SHP-1 inhibitors with anti-tumor activity likely via an immune mechanism, supporting SHP-1 as a novel target for cancer treatment.

Targeted therapies for non-clear renal cell carcinoma

The treatment of advanced and metastatic kidney cancer has been revolutionized by the development of targeted systemic therapies. Despite the growing number of available agents approved for use against clear cell renal cell carcinoma, patients with non-clear histologies, constituting approximately 1 in 4 cases of kidney cancer, have not received the same attention. The majority of clinical trials testing novel targeted therapies have excluded non-clear subtypes, providing limited therapeutic options for patients with these diagnoses and their oncologists. This review will focus on the use of targeted therapies against the non-clear histologic subtypes of renal cell carcinoma: papillary I and II, chromophobe, and collecting duct. The unique genetic and molecular profiles of each distinct non-clear kidney cancer subtype will be described, as these differences are integral to the development and effectiveness of the novel agents used to treat them. Trials focusing on non-clear kidney cancer, or those that treated clear cell tumors along with significant numbers of non-clear subtypes, will be discussed. The role of cytoreductive nephrectomy and the use of neoadjuvant and adjuvant targeted therapy will be reviewed. Lastly, areas of future research will be highlighted.

(Pre-)clinical pharmacology and activity of pazopanib, a novel multikinase angiogenesis inhibitor

Pazopanib is a recently approved, novel tyrosine kinase inhibitor specifically designed to impair angiogenesis by abrogating vascular endothelial growth factor receptor 2 (VEGFR-2) to exert its function. Pazopanib inhibits VEGF-induced endothelial cell proliferation in vitro and angiogenesis in vivo and demonstrates antitumor activity in mouse models. Furthermore, the pazopanib concentration resulting in maximal inhibition of VEGFR-2 phosphorylation in vivo was in line with the steady-state concentration required to inhibit growth of tumor xenografts, suggesting that pazopanib's mechanism of action is indeed through VEGFR-2 inhibition. In a phase I trial, a generally well-tolerated dose was identified at which the majority of patients achieved pazopanib plasma concentrations above the concentration required for maximal in vivo inhibition of VEGFR-2 phosphorylation in preclinical models. Administered as monotherapy, evidence of antitumor activity was observed in phase II studies in several tumor types, including soft tissue sarcoma, renal cell cancer (RCC), ovarian cancer, and non-small cell lung cancer. Recently, the U.S. Food and Drug Administration granted approval for treatment with pazopanib in patients with RCC based on the longer progression-free survival time observed with this agent in a placebo-controlled, randomized trial. This review summarizes the preclinical and clinical pharmacokinetics and pharmacodynamics of pazopanib, as well as data on clinical activity, that ultimately resulted in its recent approval.

[Angiogenesis inhibition: review of the activity of sorafenib, sunitinib and bevacizumab]

Renal cell carcinoma accounts for approximately 3% of all human malignancies. The use of cytokines in metastatic stage of disease has been the standard until last decades, presenting partial and short duration responses. Research on angiogenesis in renal carcinoma has brought important advances to understand tumor biology and to allow us development of new antiangiogenic drugs. Sunitinib (SUTENT), sorafenib (NEXAVAR) and bevacizumab (AVASTIN) are actually three molecules accepted to use in metastatic renal cell carcinoma (mRCC), with a good tolerability demonstrated in different studies. Clinical evidence shows sunitinib to be reference standard of care for the first-line treatment of mRCC. The use of bevacizumab in combination with interferon alfa (IFN alfa) can also be considered in this setting. Sorafenib is recommended for second-line treatment in cytokine-refractory patients, sunitinib being also accepted in this situation. Other combination of these molecules and their use as neo-adjuvant and adjuvant therapy is being evaluated and should change in the short term the management of the disease.

Surgery plus targeted therapy for renal cell carcinoma with isolated spermatic cord metastasis

We present a case of renal cell carcinoma with metastasis to the ipsilateral spermatic cord. We report the clinical presentation and management of this case and review the scientific literature of this unusual case presentation.

STAT3 inhibitor WP1066 as a novel therapeutic agent for renal cell carcinoma

Background:

Signal transducer and activator of transcription 3 (STAT3) regulates the expression of genes that mediate cell survival, proliferation, and angiogenesis and is aberrantly activated in various types of malignancies, including renal cell carcinoma (RCC). We examined whether it could be a novel therapeutic target for RCC by using the STAT3 inhibitor WP1066.

Methods:

The antitumour activities and related mechanisms of WP1066 were investigated in vitro on renal cancer cell lines and in vivo on murine xenografts.

Results:

In Caki-1 and 786-O renal cancer cells, 5 μM WP1066 prevented the phosphorylation of STAT3, and 2.5 μM WP1066 significantly (P<0.01) inhibited cell survival and proliferation. WP1066 suppressed the expression of Bcl-2, induced apoptosis, and inhibited the basal and hypoxia-induced expression of HIF1α and HIF2α, as well as vascular endothelial growth factor secretion into cell culture medium. Human umbilical vascular endothelial cells cocultured with media from WP1066-treated cells showed significantly reduced tubulogenesis (P<0.05). Systemic oral administration of WP1066 to mice for 19 days significantly inhibited the growth of Caki-1 xenograft tumours (P<0.05), and pathological analysis of xenografts of WP1066-treated mice showed decreased immunostaining of phosphorylated STAT3 and reduced length of CD34-positive vessels (P<0.05).

Conclusion:

Our results suggest that using WP1066 to inhibit the STAT3 signalling pathway could be a novel therapeutic strategy against RCC.

Direct and differential suppression of myeloid-derived suppressor cell subsets by sunitinib is compartmentally constrained

The antiangiogenic drug sunitinib is a receptor tyrosine kinase inhibitor with significant, yet not curative, therapeutic effects in metastatic renal cell carcinoma (RCC). Sunitinib is also an immunomodulator, potently reversing myeloid-derived suppressor cell (MDSC) accumulation and T-cell inhibition in the blood even of nonresponder RCC patients. We observed that sunitinib similarly prevented MDSC accumulation and restored normal T-cell function to the spleens of tumor-bearing mice, independent of the capacity of sunitinib to inhibit tumor progression (RENCA>CT26>4T1). Both monocytic and neutrophilic splenic MDSC were highly repressible by sunitinib. In contrast, MDSC within the microenvironment of 4T1 tumors or human RCC tumors proved highly resistant to sunitinib and ambient T-cell function remained suppressed. Proteomic analyses comparing tumor to peripheral compartments showed that granulocyte macrophage colony-stimulating factor (GM-CSF) predicted sunitinib resistance and recombinant GM-CSF conferred sunitinib resistance to MDSC in vivo and in vitro. MDSC conditioning with GM-CSF uniquely inhibited signal transducers and activators of transcription (STAT3) and promoted STAT5 activation. STAT5ab(null/null) MDSC were rendered sensitive to sunitinib in the presence of GM-CSF in vitro. We conclude that compartment-dependent GM-CSF exposure in resistant tumors may account for the regionalized effect of sunitinib upon host MDSC modulation and hypothesize that ancillary strategies to decrease such regionalized escape will enhance the potency of sunitinib as an immunomodulator and a cancer therapy.

Updates on novel therapies for metastatic renal cell carcinoma

Metastatic renal cell carcinoma (RCC) poses one of the great therapeutic challenges in oncology. RCC is predominantly refractory to treatment with traditional cytotoxic chemotherapies, and until recently management options were limited to immunotherapy or palliative care. However, in the past few years we have experienced a sea change in the treatment of advanced RCC with the introduction of targeted therapies that derive their efficacy at least in part through alterations in tumor angiogenesis. The tyrosine kinase inhibitors sunitinib, pazopanib, and sorafenib, the monoclonal antibody bevacizumab (in combination with interferon-α), and the rapamycin analogs, temsirolimus and everolimus, are now approved agents in the United States for the treatment of metastatic RCC. Efforts to expand upon these successes include developing novel antiangiogenic agents, optimizing concomitant and sequential regimens, identifying predictors of response to specific treatments, and further dissecting the underlying molecular pathogenesis of RCC to reveal novel therapeutic targets.

[Management of side effects associated with antiangiogenic treatment in renal cell carcinoma]

The recent development of antiangiogenic agents has revolutionized the management of renal cell carcinoma. In less than two-years, the French health authorities have approved the use of four drugs (sorafenib, sunitinib bevacizumab, temsirolimus) for the treatment of locally advanced or metastatic renal cell carcinoma. A fifth drug (everolimus) should be on the market some time. Clinicians have changed their practice and are faced with a number of new adverse events. The management of toxic effects is essential to ensure treatment compliance and patient quality of life. The present report describes in detail the adverse events associated with each therapeutic class and the management of side effects.

The high-dose aldesleukin (IL-2) "select" trial: a trial designed to prospectively validate predictive models of response to high-dose IL-2 treatment in patients with metastatic renal cell carcinoma

For patients with metastatic renal cell carcinoma (RCC), the prognosis is poor. Despite the recent approval of drugs such as sorafenib, sunitinib, and temsirolimus, durable remissions of metastatic disease are rare. This is largely due to the fact that these drugs, while effective, do not result in the eradication of disease. In 1992, the FDA approved the use of high-dose interleukin-2 (IL-2) for the treatment of patients with metastatic RCC because of a small number of patients that achieved durable responses. However, IL-2 has not become a mainstay of treatment because of the expense and toxicity associated with this therapy. This review article discusses a phase II trial that investigates predictive biomarkers that might help clinicians identify the patient population with metastatic RCC that would benefit from IL-2 therapy and therefore limit patients who receive this toxic therapy to those most likely to benefit.

[Treatment of advanced hepatocellular carcinoma]

In the last few years, much progress has been made in the diagnosis and treatment of hepatocellular carcinoma (HCC). Due to these advances, HCC is no longer regarded as a disease with an extremely poor prognosis and has become the focus of some of the most active basic and clinical research in recent years. The most important advance is possibly the demonstration that sorafenib, a multikinase inhibitor with antiproliferative and antiangiogenic properties, is an effective treatment, able to increase survival in patients with advanced-stage HCC. This increased survival has demonstrated that these drugs, which act selectively on the molecular pathways involved in tumoral progression, can be effective in the treatment of HCC and has opened the door to the evaluation of these molecular agents, alone or in combination, in HCC. The present article provides a review of the treatment of advanced-stage HCC, with special emphasis on the distinct agents that are currently under evaluation.

Efficacy of targeted therapy in patients with renal cell carcinoma with pre-existing or new bone metastases

INTRODUCTION

This single-centre retrospective analysis of data from three randomised studies and two expanded-access studies compared the effect of interferon (IFN)-alfa, sunitinib, and sorafenib on the occurrence and progression of metastatic bone lesions in patients with renal cell carcinoma (RCC).

METHODS

The analysis included 292 patients: 107 received sunitinib 50 mg/day in 6-week cycles (Schedule 4/2), 147 received sorafenib 800 mg/day, and 38 received placebo or IFN-alfa 9 MU t.i.w.

RESULTS

Pre-existing metastatic bone lesions were reported in 82 patients, of which 30 experienced progression. Twenty-three of 210 patients developed new bone lesions. Overall, sunitinib appeared slightly more effective than sorafenib or IFN-alfa at extending mean time to progression of pre-existing bone lesions (P = 0.057). Compared with sorafenib, sunitinib significantly decreased formation (P = 0.034) and prolonged time to occurrence of new bone lesions (P = 0.047).

CONCLUSION

Further evaluation of the effect of these therapies on bone metastases in RCC is warranted.

Update on systemic therapies of metastatic renal cell carcinoma

PURPOSE

Recent advances in understanding the molecular biology of advanced and metastatic renal cell carcinoma (RCC) have led to the development of several targeted agents that show impressive antitumor efficacy. The integration of these drugs into clinical practice has revolutionized the therapeutic management of RCC.

METHODS

We reviewed data on all approved targeted agents in the first-line and second-line setting, as well as, studies involving sequential therapy. Data from phase III trials are discussed, and an optional therapeutic algorithm is presented.

RESULTS

Sunitinib should be used as the first-line treatment of choice for good- and intermediate-risk patients according to Memorial Sloan-Kettering Cancer Center (MSKCC) criteria, whereas temsirolimus is recommended for the poor-risk group. The combination of bevacizumab and INF-alpha can be regarded as an alternative to sunitinib. After cytokine failure, patients should be recommended to sorafenib. Everolimus must be considered after first-line failure of a tyrosine kinase inhibitor (TKI); furthermore, recent evidence suggests sequential use of TKIs before administration of everolimus.

CONCLUSIONS

A range of potent drugs are available to patients with metastatic RCC. Treatment decisions should be made carefully taking into consideration that all targeted agents only have a palliative effect with prolongation of life, but do not cure metastatic RCC.

Update on novel agents in renal cell carcinoma

Renal cell carcinoma (RCC) is a disease with a variable natural history, sometimes presenting with a very indolent course and other times with an aggressive clinical course and unusual sites of metastasis. Surgical resection for stage I-III tumors represents the standard of care and is the only curative option available to patients. However, 40-50% of patients develop metastatic disease. Prior to the advent of targeted therapy, cytokine therapy was the only treatment for RCC. The administration of high-dose, bolus IL-2 has historically produced consistent, durable responses in a small percentage of patients with advanced RCC. The use of IFN-alpha is currently limited to combination therapies. Multiple new agents targeting the VEGF pathway have been tested and approved, including sunitinib, sorafenib and bevacizumab, with others waiting in the wings. In the majority of cases these drugs induce disease stabilization with eventual disease progression. Hence additional new pathways are being targeted and studied. Mechanisms of drug resistance, novel combinations, sequences and schedules are the focus of current clinical investigations. This review provides an updated list of the novel targeted agents in advanced clinical development for metastatic RCC.

Systemic therapy of kidney cancer: tyrosine kinase inhibitors, antiangiogenesis or IL-2?

The von Hippel-Lindau (VHL) tumor suppressor gene is mutated in at least 50% of sporadic clear-cell renal cell carcinoma (RCC). This leads to a pseudohypoxic state in which the pVHL complex does not degrade hypoxia-inducible factor. Subsequent intracellular hypoxia-inducible factor accumulation results in increased production of growth factors such as VEGF, responsible for angiogenesis, tumor proliferation and mitogenesis. Recently, a number of strategies have been designed to specifically target these pathways. The VEGF, its related receptor and the mammalian target of rapamycin (mTOR) signal transduction pathway, in particular, have been utilized as therapeutic targets. Clinical trials have demonstrated the survival benefit of these agents, particularly in clear-cell RCC. Today, sunitinib is recommended as first-line therapy for intermediate- or low-risk patients with metastatic RCC. Sorafenib is advised as second-line therapy, whereas temsirolimus is generally recommended as first-line treatment in high-risk patients. Everolimus is the new standard following sunitinib. High-risk patients appeared to benefit less than low-risk patients from bevacizumab plus IFN-alpha therapy. High-dose IL-2 has been proven effective in prolonging progression-free survival or overall survival, depending on risk group selection criteria. Although novel agents show a consistent effect as measured by objective response, no currently available data demonstrate that these agents will cure any patient.

Gene-modified tumor vaccine secreting a designer cytokine Hyper-Interleukin-6 is an effective therapy in mice bearing orthotopic renal cell cancer

Although renal cell cancer (RCC) is known to be immunogenic, clinical efficacy of various immunotherapeutic approaches remains unsatisfactory. Novel targeted therapies showing cytostatic rather than cytotoxic activity are unable to cure RCC patients. In our studies, we evaluated the therapeutic efficacy of whole-cell vaccine based on irradiated murine RENCA cells genetically modified to secrete designer cytokine--Hyper-IL6 (H6)--comprising IL-6 and soluble IL-6 receptor. An orthotopic RCC model based on a subcapsular implantation of RENCA cells into kidneys of Balb/C mice was employed. The efficacy of RENCA-H6 vaccine was compared with control vaccine (RENCA-wt) in relation to naive (non-immunized) animals. Three sets of vaccination experiments were carried out in a (i) protective, (ii) palliative and (iii) adjuvant (following nephrectomy) setting. The influence of vaccination on survival of RCC-bearing animals was analyzed. Specificity of vaccine-induced immune response was studied using model antigen-GFP. RCC-bearing animals immunized with RENCA-H6 vaccine showed prolonged survival compared with other groups. In palliative and adjuvant settings the survival RENCA-H6-immunized animals exceeded 75%. Administration of RENCA-H6 inhibited formation and recruitment of Treg cells (CD4+CD25+Foxp3+) and increased maturation of DCs. RENCA tumors in RENCA-H6- vaccinated animals contained large populations of NK cells and activated CD4+, CD8+ T cells. In addition, in mice vaccinated with RENCA-H6 cells large population of CD4+ and CD8+ memory cells (CD62Llow) were detected. In the orthotopic RCC model, RENCA-H6 vaccine showed high therapeutic potential, which resulted from modulation of numerous immunological mechanisms.

Anti-vascular endothelial growth factor therapies and cardiovascular toxicity: what are the important clinical markers to target?

BACKGROUND

Therapies targeting vascular endothelial growth factor (VEGF) are associated with hypertension, cardiotoxicity, and thromboembolic events.

METHODS

All prospective phase I-III clinical trials published up to December 2008 of approved anti-VEGF therapies (bevacizumab, sunitinib, sorafenib) and relevant literature were reviewed.

RESULTS

The rates of Common Toxicity Criteria (version 3) grade 3-4 hypertension with bevacizumab, sunitinib, and sorafenib were 9.2%, 6.9%, and 7.2%, respectively. Grade 3-4 left ventricular systolic dysfunction was noted in 0.3%, 1.4%, and 0.05% of patients, respectively, whereas the rates of grade 3-4 thromboembolism were 9.6%, 1.2%, and 3.8%, respectively. The renin-angiotensin-aldosterone system (RAAS) may play a key role in vasoconstriction and capillary rarefaction, which are unleashed when VEGF signaling is targeted. Inhibiting RAAS may be the optimal approach for managing these toxicities.

CONCLUSIONS

In anticipation of cardiovascular complications with anti-VEGF therapies, early detection and personalized management may improve clinical outcomes and tolerance.

Bevacizumab as a treatment option in advanced renal cell carcinoma: an analysis and interpretation of clinical trial data

The availability of molecularly targeted agents has improved outcomes for patients with renal cell carcinoma (RCC), a disease long considered refractory to systemic therapy. The hypervascularity observed in RCC tumors, which is driven by the inactivation of the vonHippel-Lindau gene, provided a rationale for targeting angiogenesis, in particular vascular endothelial growth factor (VEGF). Bevacizumab, a potent and specific anti-VEGF monoclonal antibody, has demonstrated significant clinical benefits when used in combination with interferon-alfa (IFN-alpha) for the treatment of metastatic RCC in two randomized phase III trials. The use of bevacizumab with IFN-alpha received approval in Europe for the first-line treatment of patients with advanced or metastatic RCC, and more recently this combination was approved for use in patients with mRCC in the United States. Bevacizumab with IFN-alpha has also been recommended by the National Comprehensive Cancer Network for first-line therapy of relapsed or metastatic unresectable RCC with predominantly clear cell histology. Two phase II studies suggest that bevacizumab has single-agent activity, which is characterized by encouraging progression-free survival rates and evidence of tumor regressions in patients with advanced or metastatic RCC. Here we review these trials along with recent and ongoing studies that explore the combination of bevacizumab with other targeted agents, its optimal sequencing with tyrosine kinase inhibitors, and its combination with low-dose IFN-alpha. Collectively, these studies allow the role of bevacizumab-based therapy to be defined in the context of a new and evolving algorithm for the treatment of patients with advanced RCC.

Phase 1 study of the investigational, oral angiogenesis inhibitor motesanib in Japanese patients with advanced solid tumors

PURPOSE

The aim of this study was to investigate the safety and pharmacokinetics of motesanib (AMG 706), a small-molecule antagonist of vascular endothelial growth factor receptors 1, 2, and 3, platelet-derived growth factor receptor, and c-Kit in Japanese patients with advanced solid tumors.

METHODS

Patients were administered motesanib orally once daily (QD) at doses of 50, 100, and 125 mg QD. The total study duration for each patient consisted of three cycles of 28 days per cycle. The primary endpoints were the incidence of dose-limiting toxicities (DLTs), estimation of the maximum tolerated dose (MTD), and assessment of pharmacokinetic parameters of motesanib.

RESULTS

Fifteen patients were enrolled and received motesanib. No DLTs were observed and, therefore, the MTD was not reached. Motesanib had acceptable toxicity at doses up to 125 mg QD. The pharmacokinetics of motesanib appears to be dose proportional. No objective responses per RECIST were observed. However, all 15 patients achieved stable disease, and five patients had durable (>24 weeks) stable disease.

CONCLUSIONS

The results of this study demonstrate that motesanib is tolerable in Japanese patients at doses up to 125 mg QD.

A pilot clinical trial testing mutant von Hippel-Lindau peptide as a novel immune therapy in metastatic renal cell carcinoma

Background

Due to the lack of specific tumor antigens, the majority of tested cancer vaccines for renal cell carcinoma (RCC) are based on tumor cell lysate. The identification of the von Hippel-Lindau (VHL) gene mutations in RCC patients provided the potential for developing a novel targeted vaccine for RCC. In this pilot study, we tested the feasibility of vaccinating advanced RCC patients with the corresponding mutant VHL peptides.

Methods

Six patients with advanced RCC and mutated VHL genes were vaccinated with the relevant VHL peptides. Patients were injected with the peptide mixed with Montanide subcutaneously (SQ) every 4 weeks until disease progression or until the utilization of all available peptide stock.

Results

Four out of five evaluable patients (80%) generated specific immune responses against the corresponding mutant VHL peptides. The vaccine was well tolerated. No grade III or IV toxicities occurred. The median overall survival (OS) and median progression-free survival (PFS) were 30.5 and 6.5 months, respectively.

Conclusions

The vaccine demonstrated safety and proved efficacy in generating specific immune response to the mutant VHL peptide. Despite the fact that the preparation of these custom-made vaccines is time consuming, the utilization of VHL as a vaccine target presents a promising approach because of the lack of other specific targets for RCC. Accordingly, developing mutant VHL peptides as vaccines for RCC warrants further investigation in larger trials. Trial registration: 98C0139

Tumour microvessel endothelial cell KIT and stem cell factor expression in human solid tumours

AIMS

To assess KIT receptor tyrosine kinase and stem cell factor (SCF, KIT ligand) expression in tumour microvessel endothelial cells.

METHODS AND RESULTS

KIT and SCF expression were studied in 248 human tumours consisting of 15 different histological types using immunohistochemistry and in situ hybridization for KIT messenger RNA. Moderate to strong intratumoral endothelial cell KIT expression was present in 11 of the 15 tumour types, and was most common in glioblastoma (58%), mixed embryonal carcinoma with teratoma (33%) and renal clear cell carcinoma (29%). Results of in situ hybridization were in line with those obtained with immunohistochemistry in the cases studied (n = 9). Marked SCF expression was uncommon in tumour endothelial cells, but frequent in perinecrotic tumour cells. Patients with glioblastoma with moderate to strong endothelial cell KIT expression had more favourable survival than those whose tumour showed little or no expression (P = 0.024). Glioblastoma patients whose tumour expressed SCF had an unfavourable outcome compared with those with tumour with weak or no expression (P = 0.034).

CONCLUSIONS

Intratumoral microvessels of several types of human malignant tumours express KIT. Tumour cell SCF expression and absence of marked endothelial cell KIT expression are novel adverse prognostic features in glioblastoma.

Sunitinib and sorafenib in metastatic renal cell carcinoma patients with renal insufficiency

BACKGROUND

Although clinical trials with sunitinib and sorafenib in metastatic renal cell carcinoma (mRCC) have included patients with moderate renal insufficiency (RI), the incidence of renal toxicity induced by their administration as well as the safety of these agents in patients with more severe renal insufficiency has not been extensively reported.

PATIENTS AND METHODS

Patients with mRCC treated with vascular endothelial growth factor-targeted therapy with either RI at time of treatment initiation or who developed RI during therapy were identified. RI was defined as serum creatinine (Cr) > or = 1.9 mg/dl or a creatinine clearance (CrCl) < 60 ml/min/1.73 m(2) for >3 months before treatment. Objective outcomes and toxic effects of treatment were also measured.

RESULTS

A total of 39 patients were identified: 21 patients who initiated therapy with preexisting RI and 18 patients who developed RI during treatment. In patients with RI at the start of therapy, Cr increased in 57%, and 48% of patients required dose reduction. The median time to maximum RI was 6.6 months (range 0.4-19.6 months). In patients who developed RI while receiving therapy, median serum Cr and CrCl at the start of therapy were 1.5 mg/dl (range 1.1-1.8) and 61 ml/min (range 43-105), respectively. Patients experienced a median increase in serum Cr of 0.8 mg/dl (range 0.3-2.8) and a median decrease in CrCl of 25 ml/min (range 8.54-64.76). Overall, 5 patients (24%) achieved a partial response (PR), 13 (62%) had stable disease (SD) and 3 (14%) had progressive disease (PD). Estimated progression-free survival (PFS) was 8.4 months. The most common toxic effects (all grades) were fatigue (81%), hand-foot syndrome (HFS) (52%) and diarrhea (48%). Six patients experienced grade III toxicity (29%), primarily HFS.

CONCLUSIONS

Sunitinib and sorafenib can be safely given to patients with renal insufficiency, provided adequate monitoring of renal function. For those patients developing an increase in Cr, dose modifications may be required to allow continuation of therapy. The clinical outcome of patients with baseline renal dysfunction and patients who develop renal dysfunction does not appear to be compromised.

Pazopanib

In October 2009, pazopanib (Votrient; GlaxoSmithKline)--a multikinase inhibitor with targets that include vascular endothelial growth factor receptors--was approved by the US FDA for the treatment of advanced renal cell carcinoma.

Cardiomyocyte PDGFR-beta signaling is an essential component of the mouse cardiac response to load-induced stress

PDGFR is an important target for novel anticancer therapeutics because it is overexpressed in a wide variety of malignancies. Recently, however, several anticancer drugs that inhibit PDGFR signaling have been associated with clinical heart failure. Understanding this effect of PDGFR inhibitors has been difficult because the role of PDGFR signaling in the heart remains largely unexplored. As described herein, we have found that PDGFR-beta expression and activation increase dramatically in the hearts of mice exposed to load-induced cardiac stress. In mice in which Pdgfrb was knocked out in the heart in development or in adulthood, exposure to load-induced stress resulted in cardiac dysfunction and heart failure. Mechanistically, we showed that cardiomyocyte PDGFR-beta signaling plays a vital role in stress-induced cardiac angiogenesis. Specifically, we demonstrated that cardiomyocyte PDGFR-beta was an essential upstream regulator of the stress-induced paracrine angiogenic capacity (the angiogenic potential) of cardiomyocytes. These results demonstrate that cardiomyocyte PDGFR-beta is a regulator of the compensatory cardiac response to pressure overload-induced stress. Furthermore, our findings may provide insights into the mechanism of cardiotoxicity due to anticancer PDGFR inhibitors.

Lack of association between excretion of sorafenib in sweat and hand-foot skin reaction

STUDY OBJECTIVE

To determine if excretion of sorafenib in sweat is associated with hand-foot skin reaction in patients receiving sorafenib.

DESIGN

Prospective pilot study.

SETTING

Outpatient clinic of a cancer research institution.

PATIENTS

Two patients who were receiving sorafenib and developed a hand-foot skin reaction of at least grade 1 and two healthy subjects (controls).

INTERVENTION

Sweat production was stimulated in both the patients with hand-foot skin reaction and the healthy subjects by means of pilocarpine iontophoresis.

MEASUREMENTS AND MAIN RESULTS

Sweat samples were collected from the patients with hand-foot skin reaction and from the healthy subjects. Using liquid chromatography-tandem mass spectrometry, sorafenib concentrations were measured in the sweat samples. Sweat samples from the healthy subjects were spiked with known concentrations of sorafenib to determine the lower limit of quantification of the assay, which was determined to be 5 ng/ml. Sorafenib concentrations in the samples from the patients with hand-foot skin reaction were undetectable based on the assay's sensitivity.

CONCLUSION

Our results suggest that hand-foot skin reaction in patients receiving sorafenib is not associated with excretion of sorafenib in sweat. Further studies are needed to understand the mechanism of hand-foot skin reaction, a treatment-limiting adverse effect of multikinase inhibitors.

Compounds in clinical Phase III and beyond

Targeted therapies against cancer have become more and more important. In particular, the inhibition of tumor angiogenesis and vascular targeting have been the focus of new treatment strategies. Numerous new substances were developed as angiogenesis inhibitors and evaluated in clinical trials for safety, tolerance, and efficacy. With positive study results, some of these molecules have already been approved for clinical use. For example, this is true for the vascular endothelial growth factor neutralizing antibody bevacizumab (BEV) in metastatic colorectal cancer, nonsmall cell lung cancer, renal cancer, and breast cancer. The tyrosine kinase (TK) inhibitors sorafenib and sunitinib have been approved for metastatic renal cancer as well as for hepatocellular carcinoma, and sunitinib has also been approved for gastrointestinal stroma tumors. In this chapter we try to give an overview of the substances currently investigated in Phase III studies and beyond with regard to antiangiogenesis in cancer therapy.

Sunitinib

Sunitinib is an oral multikinase inhibitor that blocks the vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR) alpha and beta, c-kit, and other receptors. These attributes have proven to be efficacious in the treatment of metastatic renal cell carcinoma (RCC) and unresectable gastrointestinal stromal tumors (GIST). Most side effects, including hypertension, hand-foot syndrome, and diarrhea are generally well manageable. Clinical trials are underway to determine the efficacy of sunitinib in other tumor types including metastatic breast, colorectal, and lung cancers. This chapter will detail the preclinical data leading to the results of the pivotal phase III clinical trials that have led to the widespread use of sunitinib in metastatic RCC and advanced GIST.

New treatment approaches in renal cell carcinoma

Metastatic renal cell carcinoma (RCC) is notoriously chemoresistant; up until recently, immunotherapy (in particular interferon-alpha) has represented the treatment of choice. The understanding of the biology of RCC has resulted in the development of targeted therapies. In particular, multikinase inhibitors (sunitinib, sorafenib, axitinib, pazopanib), antivascular endothelial growth factor agents (bevacizumab), and mammalian target of rapamycin inhibitors (temsirolimus, everolimus) now have a role in the approach to different subsets of RCC. Sunitinib is indicated for the first-line therapy of metastatic RCC as a consequence of a positive phase III trial versus interferon-alpha; sorafenib is now registered for the second-line treatment of RCC, which was earlier treated with cytokine as a consequence of a positive phase III trial versus placebo. Bevacizumab is also indicated in the first-line treatment of metastatic RCC given in combination with interferon-alpha as a consequence of two positive phase III trials. Temsirolimus, unlike the other agents, has also shown activity in poor-prognosis patients, and is now the treatment of choice in previously untreated poor-prognosis RCC as a single agent. Everolimus can be considered as the best therapeutic option in patients with RCC pretreated with targeted agents as a consequence of a positive phase III study versus best supportive care. Markers for appropriate treatment selection, combined use of targeted agents, treatment of special histologies, and adjuvant and neoadjuvant setting represent important special issues to be dealt with in future studies.

Antivascular therapy for epithelial ovarian cancer

Ovarian cancer is the fifth largest cancer killer in women. Improved understanding of the molecular pathways implicated in the pathogenesis of ovarian cancer has led to the investigation of novel targeted therapies. Ovarian cancer is characterized by an imbalance between pro- and antiangiogenic factors in favor of angiogenesis activation. Various antivascular strategies are currently under investigation in ovarian cancer. They can schematically be divided into antiangiogenic and vascular-disrupting therapies. This paper provides a comprehensive review of these new treatments targeting the tumor vasculature in this disease. Promising activities have been detected in phase II trials, and results of phase III clinical trials are awaited eagerly.

Phase 1b study of motesanib, an oral angiogenesis inhibitor, in combination with carboplatin/paclitaxel and/or panitumumab for the treatment of advanced non-small cell lung cancer

PURPOSE

Motesanib is a small-molecule antagonist of vascular endothelial growth factor receptor 1, 2, and 3, platelet-derived growth factor receptor, and Kit. This phase 1b study assessed the safety, maximum tolerated dose (MTD), and pharmacokinetics, and explored the objective response of motesanib plus carboplatin/paclitaxel and/or the fully human anti-epidermal growth factor receptor monoclonal antibody panitumumab in advanced non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Patients with unresectable NSCLC received sequentially escalating doses of motesanib [50, 125 mg once daily; 75 mg twice daily] orally continuously plus carboplatin/paclitaxel (arm A; first line) or panitumumab (arm B; first and second line) once every 21-day cycle or 125 mg once daily plus carboplatin/paclitaxel and panitumumab (arm C; first line).

RESULTS

Forty-five patients received motesanib. Three dose-limiting toxicities occurred: grade 4 pulmonary embolism (n = 1; arm A, 50 mg once daily) and grade 3 deep vein thrombosis (n = 2; arm A, 125 mg once daily; arm C). The MTD was 125 mg once daily. Common motesanib-related adverse events were fatigue (60% of patients), diarrhea (53%), hypertension, (38%), anorexia (27%), and nausea (22%). Three cases of cholecystitis occurred but only in the 75-mg twice-daily schedule, which was subsequently discontinued. At 125 mg once daily, motesanib pharmacokinetics were not markedly changed with carboplatin/paclitaxel coadministration; however, exposure to paclitaxel was moderately increased. The objective response rates were 17%, 0%, and 17% in arms A, B, and C, respectively.

CONCLUSIONS

Treatment with motesanib was tolerable when combined with carboplatin/paclitaxel and/or panitumumab, with little effect on motesanib pharmacokinetics at the 125-mg once daily dose level. This dose is being investigated in an ongoing phase 3 study in NSCLC.

Vascular endothelial growth factor pathway-targeted therapy as initial systemic treatment of patients with renal cancer

Advanced renal cancer is known to be largely refractory to traditional DNA- and DNA repair-targeted chemotherapy. Until recently, immunotherapy had been the mainstay for the treatment; however, it is effective in only a small proportion of patients. Advances in the understanding of the association between the von Hippel-Lindau pathway and angiogenesis and their role in the development of renal cancer has led to the development of highly effective vascular endothelial growth factor (VEGF) pathway-targeted inhibitors. Several such novel agents have demonstrated increased clinical benefit, progression-free survival, and superior quality of life in large, randomized phase III clinical trials, and additional VEGF pathway inhibitors are currently being studied. This review will summarize the major clinical trials and practical recommendations for the most studied VEGF inhibitors, including sunitinib, sorafenib, and bevacizumab; introduce novel VEGF inhibitor agents; outline side effects and toxicities; and discuss sequential and combination therapy with these agents.

Novel antiangiogenic agents in the treatment of refractory renal cell carcinoma

The approvals of sunitinib, sorafenib, and temsirolimus have dramatically altered the management of renal cell carcinoma. The combination of bevacizumab and interferon-alpha was recently approved in Europe and could receive regulatory approval in the United States. A recent randomized trial reported improved outcomes with everolimus following first-line tyrosine kinase inhibitors (TKIs). Despite enhanced outcomes with these agents, they are not curative, and more effective therapy is essential. Other novel antiangiogenic agents are being evaluated, including TKIs, monoclonal antibodies, and agents against other novel targets. Additionally, novel combinations of antiangiogenic agents are emerging. The rapid expansion in the therapeutic armamentarium holds the promise of further enhancing outcomes.